A surgical microscope of the kind described above is known from US 2008/0297892. This surgical microscope is designed as an ophthalmologic surgical microscope. This surgical microscope has an illuminating arrangement with which an illuminating beam path can be adjusted with the illuminating beam path running coaxially to the stereoscopic viewing beam paths. The illuminating beam path is guided through the microscope main objective to the object region. For this purpose, a beam deflection unit is provided for the surgical microscope which is configured as a beam splitter. With the beam deflection unit, the illuminating light is superposed on the left and right stereoscopic beam paths. This illuminating beam path makes possible the examination of the patient eye with excellent contrast with red reflection illumination.
Ophthalmologic surgical microscopes having an illuminating arrangement for red reflection illumination are used in cataract surgery.
In ophthalmology, so-called slit lamps are applied in order to visualize membranes in the vitreous body of a patient eye or to make structures on the retina and on the cornea of the patient eye visible. With this apparatus, a very bright slit-shaped, sharply limited light beam can be thrown from the side onto the patient eye in order to examine the same with this illumination using the microscope. This illuminating configuration is especially used in retina surgery.
Accordingly, for ophthalmologic surgical microscopes, there is the need that this is equipped for red reflection illumination as well as for slit illumination.
In retina surgery, surgical microscopes are used wherein a slit illumination module is mounted on the side facing toward the object region and ahead of the microscope main objective.
In this way, a patient eye can be examined with slit illuminating light which incidents on the object region at a large inclined angle of incidence. However, such a silt illuminating module reduces the free work space under the surgical microscope. In addition to the light source for the illuminating arrangement of the surgical microscope, an additional light source is needed for one such slit illumination module. Accordingly, a sterile manipulation of corresponding slit illuminating modules is difficult in day to day surgery.
There are surgical microscope known having an illuminating arrangement for the slit illumination wherein the slit illuminating light is guided through the microscope main objective to the object region. Corresponding surgical microscopes are described, for example, in EP 1 300 109 A1 or in US 2006/0238711 A1. In the surgical microscopes known from US 2006/0238711 A1 or EP 1 300 109 A1, the adjustment of a beam path for red reflection illumination is, however, not provided.